Boiler



J. H. FOX

July 2, 1929.

BOILER Filed Sept. '7, 1927 lKHEIEHINEIII! INVENTOR JHIFOX Patented July2, 1929.

JONAS H. FOX, 01? SEATTLE, WASHINGTON.

. i BOILER.

Application filed September 7, 1927. Serial No. 217,952.

This invention relates to improvements in boilers and more particularlyto a fire tube boiler of the externally fired type, wherein the fire boxis surrounded by water legs which, at their upper ends, communicate withthe. boiler proper and which form the walls of a fire box.

It is the principal object ofthe present invention to provide ahorizontal, fire tube boiler of the above character embodying certainnovel features in water leg construction whereby an accelerated and moresatisfactory circulation of water is produced than in the ordinaryconstruction, so that quicker heating and greater boiler efficiency isobtained.

Other objects of the invention reside in the various details ofconstruction and in the relation of parts whereby the above results areaccomplished and whereby a commercially practicable and very desirableboiler is produced. 1

In accomplishing these objects, I have pro vided the improved details ofconstruction,

' the preferred forms of which are illustrated in the accompanyingdrawings, wherein- Figure 1 is a view, shown one-half in transversevertical section and one-half in front elevation, of a boilerconstructed in accordance with the present invention;

Figure 2 is a longitudinal, vertical section of the same.

Referring more in detail to the drawings-- The boiler, as illustrated,comprises a horizontally disposed, cylindrical shell, or boiler portionproper, designated by reference numeral 1, which is closed at itsopposite ends by flue sheets 2 and 3. Communicating with the boiler atits opposite sides, also at the front and rear ends, are water legs,presently described in detail, which form the walls of the fire box orcombustion chamber 1; this being provided at the front end with theusual opening 5 for firing.

The cylindrical body portion 1 contains the spaced apart upper and lowersets of fire tubes extending from end to end there of through the fluesheets 2 and 3. The lower set of tubes, designated by numeral 6, leadforwardly from an auxiliary combustion chamber 7 provided in opencommunication with the rear end of the main fire box between the rearWater leg and lower rear end portion of the boiler, and open into asmoke box 8 at the front end of the boiler, while the upper set of tubes9 lead rearwardly from the smoke box 8 and into a rear smoke box, orflue connection, 10.

The water legs at the sides and ends of the fire box, or furnace, areformed by spaced apart, inner and outer plates 1112 joined in spacedrelation by stay bolts 13, and are welded, or otherwise suitably fixed,to the boiler shell. The water legs at the opposite sides ofthe boiler,which are designated at 15, communicate with the interior of the boiler1 through a plurality ,of spaced apart, vertical slots 16 provided intheopposite sides of the boiler shell. The Water leg at the front,designated at l'r', opens directly across its entire end, as at 18, intothe front end of the boiler, while the water leg 19, at the rear, is setback somewhat beyond the boiler end providing the combustion ehamher 7,and at its upper end is curved over gradually so as to terminate in ahorizontally directed portion 20 which is joined with the rear fluesheet3 and which opens into the boiler through a horizontal slot 21 that extends substantially the width of the boiler at just below itsdiametrical center and in alinement with a horizontally extending spacethat is left between the upper and lower sets of fire tubes.

The most important feature of this invention resides in the constructionof the rear water leg and its relation to the boiler. It

readily apparent that, since the direction of circulation of water willcorrespond to the direction of the travel of flame or heat, there willbe a greatly accelerated circulation of water upwardly through the rearwater leg, because of the travel of heat upwardly along this leg andinto the fire tubes. Water circulating upwardly through this leg willdischarge into the boiler through the slot 21 with an accelerated flowwhich will carry it to or well toward the forward end of the boiler. Inits forward flow it will be distributed laterally to the slots 16 forpassage to the side water legs for re-circulation back to the rear andagain up through the rear leg and into the boiler.

lVhile it is well known that boilers of a type having connecting waterlegs at sides and ends and forming the fire box have been used for manyyears, it is thought to be new in the art to construct the rear waterleg, with the laterally curved upper end portion, as shown in Figure 2,and to so connec t it rwith'the boiler that the inflow 0t water fromthis leg into the boiler, accelerated by the application of heat theretoand further the same manner as the front legof the present type isshown, resulting in a vertical upfiowof water from the leg into theboiler with an eddying effect and a retarded circulation.:, V e y a "Thepresent boiler, because of the hori- 'zontal discharge oztfwater fromthe leg 19,

and the unrestricted space between the upper and lower sets of tubesinto which this water'is del1vered, efi"ects a rapid and effectivecirculation that results in quick and etfective'heating with a minimumfuel consuniptioir.

Havin g thus described my invention, what I claim as new therein anddesire to secure by Letters Patent, is:

A horizontal fire tube boiler oi: the character described having anupper and a lower set of tubes slightly spaced apart to leave anintermediate, unrestricted area said shell being provided across one endwith a horizontal opening alined with said unrestricted area, water legsconnected at their upper ends with the shell at its opposite ends andsidesand forming the walls of a tire box; the legs at opposite ends ofthe box being adapted, respectively, to contain downwardly and upwardlycirculating water with the leg which carries the upwardly eireulatingwater curved gradually at its upper end from vertical to a horizontaldirection and connected to the shell through said'horizontal end openingso that the [low of water therefrom will be unretardcd and deliveredhorizontally into the shell.

Signed at Seattle, \Vushington, this 22nd day of August, 1927.

- JONAS H. FOX.

